Screen



F. E. MHCK Er Al. 1,984,891' 4 SCREEN Dec. 18, 1934.

e Sheets-sheet 2 l Filed June 18, 1931 F. E. MIICK ET AL SCREEN 6Sheets-Sheet 5 Filed June 18, 1931 I Dec..18, 1934. VF. E. MncK Er ALSCREEN Filed June 18, 1931 6 Sheets-Sheet 4 Inman 0715' I'rederz'cZJzz'c/ Dec. 1s, 1934.,v

F. E. MIICK El' AL SCREEN 6 Sheets-Sheet Filed June 18. 1951 2.7 WWJ/va, VT, ,www w 77. .t U# Y JZ fr ff@ 707,/

l Dc. 18, 1934. l F. E. MHCK Er AL- 1,984,891

SCREEN Filed June 18, 1931 e shets-sheet 6 Patentedv Dec. 18,1934 l1,934,891

UNITED STATES PATENT?oFFicEI f issuer SCREEN Frederick E. Muck,Philadelphie, and Frederick E. Munn-111km ruk, re., signers u Linkmit(sompany, Chicago, lll., a corporation of Application June 18,1931,serial No. 545,212 11 claims. (ci. 21o- 116) This invention relates to ascreen, preferably the screen and its associated'mechanism..` The a barscreen, and to ameans and an apparatus framework may comprise verticalmembers B for cleaningthe screen. and inclined track members B1 whichare joined It has for one object to provide a sectional -at their upperends to a platform B2 which they 4screen construction. It has foranother object. support and upon which the driving mechanism -5 toprovide an apparatus for cleaning a screen in of the screen assembly ismounted. Suitable which the screen is subjected to a minimum of crossframe members B1I may be used. Addition-v wear. Another object is toprovide a rake for al inclined frame members B4 lie generallyparcleaning the screen cleaning means. Another allel with the Vinclinedtrack members -Bl and 1U object is to provide, 'in connection with thehoistwith them extend into the space A1. A plate B5 10 ingor movingapparatus for hoisting the screen, extends between the upper ends of thelmembers an automatic means for controlling the position B4 and may befastened to them. Thisv plate is of the rake. largely situated outsideof the space A1 and does Other objects will appear from time to time notcome in contact with the material flowing in the specication and claims.f therethrough. The frame members B1 and B4 1.5 The invention isillustrated more or less diamay be joined by apron-like side members B6.

grammatically in the accompanying drawings, Attaching brackets Brl B7are positioned on the `whereinzoutside of the track members B1 B1 andare Figure 1 is a vertical cross section, showing adapted to rest uponand to be fastened to suit- 1'50 the screen in position, the screenbeing shown able supports to assist in positioning the screen- 20largelyin side elevation, with parts broken away ing assembly. Upon,the` cross frame members and parts in section; f B3 may bel positioneda-refuse chute B8 over Figure 2 is a vertical cross section on linewhich the refuse from the screening assembly 2-2 of Figure 1, showingthe screen in 4rear is discharged. Any means may be used for re- 25elevation; moving the refuse from the chute. A plate or 25 Figure 3 is aplanview showing the screen in skirt B9 may depend ,from Vthe upper edgeof position, with rake and carriage omitted; the plate B5 and overlapone side of the 4chute Figure 4 vis a transverse cross section,`takenB11 as indicated in Figure 1. on an enlarged scale at line` 4-4 ofFigure 1; The screen proper may be made ysectionally,

30 Figure 5 is a detailed'vertical sectional view, the screen beingformed of bars C which are 30 showing -the mounting of the foot of thescreen;y preferably tapered at their rear edges as at C1 l Figure 6 is atransverse vertical sectional de` and fastened by welding or otherwiseto a plutail on an enlarged scale, showing one end of rality of crossmembers C1. At their upper endsthe carriage and rake assembly; they maybe additionally tapered as at C3 to 35 Figure 7 is a vertical sectiontaken at line match the downwardly inclined flange or end 35 7-7 ofFigure 6, looking in' the direction of C4 of the plate B5.

the arrow; Y A carriage'which supports a rake, is mounted Figure 8 is aside elevation of the slack cable to move up andv down the screen. Itmoves switch, with parts broken away; along the tracks B1 and carries arake and a rake l0 Figurev 9 is a "section along the vline 9-9 ofcleaning mechanism. The rake assembly in- 40 Figure 8. A cludes two ormore' carriage members D each of Like parts are designated 'by likecharacters which has projecting inwardly from it a lug D1 throughout thespecification and drawings. in which is seated a set screw D2 which mayhave A indicates generally a wall construction deco-operating with it alocking nut D3. A shaft 4J fining a liquid chamber A1 which has suitableD4 is journaled in the carriage members D and 45 cutlets and inlets andinto and through which -from the shaft the rake mechanism is suspended.liquid to be screened is moved. A plate A2 The rake proper includes apair of side memmay be secured to the bottom wall or floor members E,each of which is provided with a hub E1 bei A, as indicated particularlyin Figuresl from which projects a lug E2. A stiffening mem- 00 and 5-The plate may be fastened t0 the oor ber E3 extends from the hub E1 andalong a por- 50 member in any suitable manner and is provided tion ofthe side arm or member E. Fastenedto with `one or moreA upwardlyprojecting pins A3 the hub .E1 is `arpair of ,lever armsl E4, E5. Ex-

Which vare adapted to receive and position the tending laterally acrossbetween the two side lower end of .the screen. armsE and fastened tothem preferably at their A suitable' framework is provided to supportlower edges, is an arcuate plate E6 which may in either direction.

have at oneside an upwardly extending flange or edge E1. Removablypositioned at the opposite edge of the plate E6 is a finger bar E8 whichhas xed or formed upon it fingers E9 which are so shaped and positionedas to extend between the bars C when they are moved into a position todo so, as shown for example in Figure 4.

Supported on the shaft D4 is a wiper assembly. This includes a pluralityof side or end members F each of which is provided with a hub F1 and alever arm F2 which is perforated for a bearing support as at F3. Abearing pin F4 is received in the perforation F3. The hubs F1 aremounted for rotation about the shaft D4. A latching cam F5 is positionedand fixed upon the shaft D4. This cam is notched as at F6. A latchinglever F7 which is provided with a hub portion Fa about which a springF12 is positioned, is supported upon the pin F4. The member F7 at itsouter end carries a latching nose F9 and at its opposite end has arelatively inclined and preferably somewhat shorter lever arm portionF10. Extending laterally across between the side members F of the Wiperassembly is a wiping plate F11 which may have at its upper edge a angeF12. F13 is a spring serving normally to hold the latch in engagement.

The driving and controlling mechanism is preferably mounted on theplatform B2. It includes a motor G upon which a solenoid brak'e G1 maybe positioned. The motor, through a flexible coupling G2 and a speedreducer G2, drives a pinion G1 which is in mesh with a gear G5 on theshaft G6, which is supported in suitable bearings. A traveling cam limitswitch Gl is mounted adjacent the gear G5 and is provided with a shaftwhich carries a pinion Ga which meshes with the gear G5 and is driven byit. Thus motion of the gear is effective upon the limit switch tocontrol the motor.

Keyed or otherwise fastened to the shaft G6 is a pair of drums H, H1.Adjacent these and loosely mounted on the shaft G6 is a pair of drumsH2, H2. Brakes H4 and H1? are positioned to engage, respectively, thedrums H2 and H3. Each of the pairs of drums H, VH2 and H1, H3 areprovided on the adjoining faces of their hubs, with overlapping portionswhich permit some relative movement of' the drums and serveV to engagethem and cause them to move as one, after a certain amount of rotationof the shaft Thus, for example, the drums H, H2 will have relativemovement at rst, when the shaft is moved in either direction, and willthereafter move in unison.

A From each of the drums H, H1 a hoisting cable or rope I extendsdownwardly and is fastened to one of the .levers E4 of the rakeassembly. From each of the drums H2, H3 a lowering cable or rope I1lextends downwardly and is fastened to one of the arms Es'of the rakeassembly.

Extending downwardly from the platforrnB2 are one or more supports J,upon each of which may be movably mounted a roller support J1 carryingaroller J2. This roller is positioned in the path of the rake assembly sothat as the latter moves along the track, the roller may contact thewiper arm- F2 and thev latcharm F10.`

Pivotally mounted beneath the frame B2 is a slack cable switch lassemblyof which one or more may be used. Each assembly includes'a shaft K,supported invbea'rng brackets K1 K1 and hav- 'ing fixed to it a pair ofarms K2 K2 which are joined at their lower ends by a shaft K3 which aflanged sheave K1 llpOIl is mounted. The

sheave may rotate upon the shaft and may also move along it. It engagesthe rope or cable I. Fixed on the shaft K is a lever arm K5 which mayhave a counter-weight K6. Fixed ,also on the shaft K is a lever arm K7which has a laterally bent portion K8 adapted to strike a switchoperating rod K9 when moved to a suitable position and thus to contactthe switch lever K1o of a switch K11.

It will be realized that whereas we have herewith shown and described apractical operative device, lnevertheless many changes might be made inthe size, shape, number and disposition of parts, without departing fromthe spirit of our invention and we wish, therefore, that our showing betaken as in a sense diagrammatic.

We have used the word cable or rope as applied to the hoisting members Iand I1. These, of course, could be changed to any suitable flexiblemeans, and where the word rope or cable occurs in the specification andclaims, it is to be understood as meaning any fiexible member whichcould be used in place of a rope or cable to raise or lower the rake.

The use andoperation of our invention are as follows:

The screen and itsassociated parts are positioned in the path of flowingliquid so that the liquid must pass through the screen. The barsintercept material and that which is larger than the spaces between thebars is caught by them and held from passing through. As will be seenparticularly from the detail in Figure 4, the bars are thicker at theirup-strearn edges than at their down-stream edges, being tapered towardthe down-stream side. The bars are preferably straight sided for adistance before the taper is commenced. Such bars offer less friction topassing liquid and minimize the loss in head. By reason of this shape ofthe bars, solids of approximately the width of the spaces between thebars which are caught on or between them will be removed by the rake.The teeth of the rake, when the latter is in raking position, normallyextend between the bars of the screen sufficiently to force solids whichhave lodged between the bars beyond the straight sided portions and tothe tapered portions where the clearance is suicient to permit furthermovement of the solids through and away from the screen. By this taperedconstruction of the screen bars, clogging up of the spaces between thebars, in parts of the screen not actually reached by the cleaningfingers of the rake. is prevented. The bars are assembled into sectionsof convenient size so that a screen can ordinarily be installed by theuse of one or more sections of bars and so that subsequent repair andrenewal may be accomplished simply and wit-hout the necessity of alwaysremoving an entire section. In the particular form shown, each of thescreen sections is provided at its lower edge with a plate having holesadapted to engage pins 'which are set into the floor of the channelthrough which liquid is to ow and the cross piece at the top, asindicated particularly in Figure 1, fits into or joins a structuralmember so as to support the .upper end of the screen bars preferablyabove the flow line.

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. poses of the present invention it is suilicient that means be providedfor reversing the direction of movementcf the rake assembly and forpreferably stopping the rake for aperiod at the lower limit of itsexcursion and for stopping it again at the upper'limit of its excursion.It is preferably stopped longer at the upper limit of its excursion than'at the lower limit and at the upper limit a cleaning operation iseffected, preferably automatic, to wipe or scrape the rake proper cleanof material which has been removed from the bars. .and brought up -by itand which has adhered to within lugs D'l -which 'form a part of or areattached to the carriages.

Journaledupon the shaft D are a pair of side arms E which preferablycarry hubs E from which project lugs E2 positioned opposite the lungs Dlof the carriages D. The relative position of the side arms and thecarriages may be adjusted by varying the' position of the set screwsD2in the lugs D, as these set screwsbear. against the lugs E2. tened atthe lower end of the side arms E is a plate preferably arcuate inshape,.which carries removably attached to it a finger-bar havingfingersof such size and shape that they can penetrate. into the space betweenthe screen bars. Double arm levers are fastened. to the hubs E1 andl bymeans of these arms, to which' cables are attached, the entire rakeassembly may be raised and the rake proper may be rotated so as to swingthe rake into and out of contact with the screen bars and plate.

y Hoisting cables I are preferably'lfastened to the levers E andlowering cables `I are fastened to -the lever ends E.

When the rake assembly is hoisted', its weight and the material on it iscarried bythe hoisting cablesv I and vthe rake is rotated into theposition shown in full lines in Figure 1. This rotating movement is madepossible by a limited amount of slack which is allowed to develop in thelowering cable I 1. When the rake assembly is lowered, slack is allowedto develop in the hoisting cable I and for an interval the assembly isthus held by the lowering cables I and thus the rake rotates into/theposition indicated in dotted lines adjacent the bottom of the screen inFigure l. This relative rotating of the rake parts occurs because thehoisting cablesare wound on drums H, H 1 which are xed von the drivenshaftand because the lowering cables are wound on drums H 2, H, which,while mounted upon the same shaft and-adapted to be driven by it, are soarranged, by means-of drum hubs, that whenever the shaft reverses itsdirection of movement there is an interval in which the shaft rotateswithout rotating the drums H 'H s as they are held, respectively,against rotation by brakes H H 5 and it is only after a certain amountof -rotation of the driving shaft that the drums H2 and Ha commence torevolve with the other drums. Thus, .with the parts in the positionindicated in dotted lines adjacent the lower end of Figure l, when thehoisting cables are drawn up, since the hoisting cables I are about thedrums H, Hl which are keyed tothe shaft G', these cables. at once moveand since the cables Il are about the drums H H which are for the momentfree for movement with relation to the shaft, these cables I `are notdrawn in and thusl at the start the only effect is upon the levers E"and the parts are .thus tilted into the position shown in full lines inFigure l. before any hoisting of the rake occurs. The drum hubs andbrakes are so arranged that only the proper amount of rotating movementcarr occur. Thereafter the drums H2 H"1 become locked to the otherdrums, and are -rotated andthe cables I are thereby drawn in at the samespeed as the cables I.

. 'In the reverse movement, when the'screen asscmbly is to be lowered,the shaft Gi is rotated and the cables I, being wound about the drums HH1, which are fixed to the shaft, are at once paid out or unwound whilethe cables I1, which are wound aboutthe drums H2 H3, which for themoment are free for movement with relation to the shaft Gsandsareheldfby the brakes, are not initially paid -out or unwound andthus the lever ends E4 are lowered for a brief period before the leversE5 commence to move. lThereafter rotating movement-occurs which rotatesthe rake assembly back into the position which is shown in the dottedline position shown -at the lower end of Figure 1. Thus in hoisting, therake is automatically brought into operative position in which the teethof the fingerbar penetrate between-the bars of -the screen and inlowering the rake is automatically b rought into position inwhich thenger bar and thel rake as a 'whole are rotated outwardly away from thescreen and it is in this positionv that the rake assembly is lowered.

Additional members. are provided in the rake assembly for cleaning orwiping the finger bar l and rake. These members move with the rakeassembly and form a part of it, but are also mounted and arranged forrelative movement with respect to the arcuate plate so that at the'proper time in the cycle of `operation of the assembly,'the wiper orscraper is automatically actuated to clean therake plate and the lingerbar'. This wiper assembly includes a pair of arms F which are mountedfor movement on the shaft D4. A latch cam is also mounted on the shaftand is keyed with respect to it. The arms F carry angularly disposedlevers F2 upon which a latch F'I is pivoted. The latch part F9 bf thelatch Fr1 normally engages a notch FG in the latch cam and so holds thewiper against movement vrelative to the shaft D4.` As the rake assemblyis moved toward the upper limit of its excursion, the outer end of thelatch lever F10 contacts a cam J2 and is depressed so that the.

latch is free to rotate out of engagement with the latch cam into theposition shown in dotted lines att the upper end of Figure l. Thereafterthe outer .end of the lever portion F2 of the wiper arms contacts thesame cam J2 and as the CII Cil

a lever frame and engaging the hoisting cable.

The roller being in engagement with the hoisting cable, will be affectedif the carriage assembly should meet an obstacle before it reaches itslowest predetermined position. If that should occur, excess slack woulddevelop in the hoisting rope o1 cable and the lever frame formed of themembers K2 K2 and the shafts K and K3, the latter carrying the sheaveK4, would rotate in a counterclockwise direction,

. as shown in Figure 8, and the member K7 would contact the switchoperating arm K9 andif moved sufiiciently would contact the switch leverK10 to operate it and stop further lowering.

It will be understood that the brakes Hl-and H5 are drag brakes' andthat they preferably engage the drums lconstantly and are in contactwith them at all times. Thus these brakes hold the loose drums fromturning when they. are not actually being driven from the hubs of thexed drums.

turning, except when they are actually being driven positively from thedrums which are xed on the shaft. The friction for this purpose can bevery slight, so slight indeed that as a result of this frictionpractically no additional power is required to overcome the resistance.

We claim: v 1 l. In combination with a screen, a rake assembly, movablypositioned with relation thereto, means for moving the rake assemblytherealong, the rake assembly including al rake adapted to be tiltedinto and out of engagement with the screen and including also a cleanermounted to move with said assembly and adapted to be moved back andforth across the rake to clean the same, and automatic means for tiltingthe rake out of engagement with the screen and for tilting it intoengagement with the screen. v

2 In eombinationwith a screen, a rake assembly, movably positioned withrelation thereto, means for moving lthe rake assembly therealong, therake assembly adapted to be tilted into andl out of engagement with thescreen, and including also Aa cleaner mounted to move with vsaidassembly and adapted to be moved back and forth across the rake to cleanthe same, and automatic-means for tilting the rake out of engagementwith the screen and for tilting-it into engagement with the screen, andfor operating the cleaner to clean the rakeA adjacent the upper limit ofits excursion.

3. In combination with a screen, a rake assembly, mova'bly` positioned`with relation thereto, means for-moving the rake assembly ytherealong,the rake assembly including a rake adapted ,to be tiltedv in to andout-of engagement with the screen and including also Aa cleaner mountedto .move with said assembly and adapted to be moved back and forthacross the rake to clean the same, and automatic The brakes are normallyjust 4tight enough to prevent the loose drums from including a rakemeans for tilting the rake out of engagement with the screen uponlowering, for tilting it into engagement with the' screen upon raisingand for operating the cleaner to clean the rake adjacent the upperlimitI of its excursion.

4'. In combination with a screen, means for cleaning the screen,including a rake assembly mounted to move along the screen, the assemblyincluding a rake, the assembly also including a wiper mountedto movewith theassembly and adapted to be moved to clean the rake, an automaticmeans for actuating the wiper, automatic .hoisting means for raising andlowering the rake along the screen, and automatic means for tilting therake into and out of engagement with the screen, said means including adriven shaft, said shaft carrying a drum iixed` upon it and a drumloosely mounted upon it, the rake assembly carrying levers, a cablejoining one lever to the fixed drum and a cable joining another lever tothe loose drum, whereby when the shaft is rotated in either directionthe cable joined to the fixed drum is 'at once moved, and whereby thecable joined to the loose drum is at first not moved.

5. In combination with a screen, means for cleaning the screen,including a vralre assembly mounted to move alongthe screen, theassembly including a rake, the assembly also including a wiper mountedlto move with the assembly and adapted to be moved to clean the rake, anautomatic means for actuating the wiper, automatic hoisting means forraising and lowering the rake along the screen, and automatic means fortilting the rake into and out of engagement with ,the screen, said meansincluding a driven shaft, said shaft carrying a drum xed upon it and adrum loosely mounted upon it for limited relative movement with respectto the xed drum in either direction about the shaft, the rake assemblycarrying two levers, a cable joining one lever to the fixed drum and acable joining the other lever to the loose drum, whereby when the shaftis rotated in either direction the cable-joined to the fixed drum is atonce moved, and whereby the cable joined to the loose drum is at rst notmoved.

6. In combination with a bar screen, means for cleaning the screenincluding a rake assembly mounted to move along the screen, the assemblyincluding a rake and adapted in one position to engage the bars, theassembly also including a wiper mounted to move with the assembly andvadapted to be moved to clean the rake, an automatic means for actuatingthe wiper, automatic hoisting means for raising and lowering the rakealong the screen, and automatic means for tilting the rake into and outof engagement with the screen, said means including a driven shaft, saidshaft carrying a drum fixed upon it and a drum loosely mounted upon itfor limited relative movement with respectto the fixed drum in eitherdirection labout the shaft, the rake assembly carrying twojlevers, a.cable joining one lever to the fixed drum and a cableA joining theother lever to the movable drum, whereby when the shaft is rotatedineither direction thecable vjoined to the fixed drum is at once moved,and

whereby the cable joined to the loose drum is at first not moved, andis, after a predetermined movement of the xed drum, moved.

'7. In combination with a screen, a cleaner therefor, including a rakeassembly. automatic means for raising and lowering the rake asseming apair of carriages, a shaft in them, rake arms fixed upon the shaft andcarrying at their outer ends a plate, a rake, the plate having a fingerbar, and wiper arms journaled on the shaft, carrying at their outer endsa wiper adapted to wipe the rake.

8. In combination with a screen, a cleaner therefor# including a rakeassembly, automatic means for raising and lowering the rake assembly,along the screen, the rake assembly including a vpair of carriages, ashaft in them, rake arms fixed upon the shaft and carrying at theirouter ends an arcuate plate, a rake, the plate having a nger bar, andwiper arms journaled on the shaft, carrying at their outer ends a wiperadapted to wipe the rake, a latch mechanism adapted normally to hold thewiper armv against rotation about the shaft, and automatic means forfreeing the wiper for movement.

-9. In combination with a screen, a cleaner therefor, including a rakeassembly, automatic means for raising and lowering the rake assem.

bly along the screen, the rake assembly including a pair of carriages, ashaft in them, rake arms iixed upon the shaft and carrying at theirouter ends an arcuate plate, a rake, the plate having a finger bar, andwiper arms journaled on the shaft, carrying at their outer ends a wiperadapted to wipe the rake, a latch mechanism adapted normally to hold thewiper arm against rotation about the shaft, and automatic means forfreeing the wiper for movement and for moving it to wipe the rakeadjacent the upper limit of its excursion.

10. In combination with a bar screen; a cleaner theref including a rakeassembly, automatic means for raising and lowering the rake assemblyalong the screen, the rake assembly including a a pair of carriages, ashaft in them, rake arms fixed upon the shaft and carrying at theirouter ends an arcuate plate, a rake, the plate having a nnger bar, andwiper arms journaled on the shaft, carrying at their outer ends a wiperadapted to wipe the rake, a latch mechanism adapted normally to hold thewiper a'rm against rotation about the' shaft and automatic means fortilting the rake into engagement with the screen bars, and automaticmeans for freeing the wiper for movement.

11. In combination with a b'ar screen, a cleaner therefor, including arake assembly, automatic v means for raising and lowering the rakeassembly along the screen, the rakel assembly including a pair ofcarriages, a shaft in them, rake arms rlxed upon theshaft and carryingat their outer ends an arcuate plate, a rake, the plate having a fingerbar, and wiper arms journaled on the shaft carrying at their outer endsa wiper adapted to wipe the rake, a latch mechanism adapted normally tohold the wiper arm against rotation about the shaft and automatic meansfor tilting the rake into engagement with the screen bars as the rakemoves upwardly, and for tilting it out of engagement with the screenbars as it'moves downwardly, and automatic means for freeing the wiperfor movement.

FREDERICK E. MIICK. FREDERICK E. MAJOR.

